ST targets cheaper solar cells for industry

WASHINGTON  STMicroelectronics unveiled details Tuesday (Sept. 30) of a solar-energy research program designed to reduce the cost of electricity generation.

Research teams based in Catania and Naples, Italy, will focus on applying the company's nanotechnology expertise to the development of new photovoltaic technologies. The announcement comes days after a huge power outage darkened most of Italy.

Photovoltaic research has long focused on increasing the efficiency of semiconductor-based solar cells. ST researchers have concluded, however, that little more can be done to improve efficiency or reduce manufacturing costs. Hence, they hope to use nanotechnology to produce cells with lower efficiencies  about 10 percent rather 15 to 20 percent  while reducing manufacturing costs.

"Existing solar cell technologies are too expensive to be used on an industrial scale. The ability to produce low cost, high efficiency solar cells would dramatically change the picture and revolutionize the field of solar energy generation, allowing it to compete more effectively with fossil fuel sources," said. Salvo Coffa, who heads the ST research group developing the new solar cell technology.

The researchers will pursue an approach called the Graetzel cell, or dye-sensitized solar cell, that mimics photosynthesis in plants.

They will also develop low-cost solar cells using a full-organic approach in which a mixture of electron-acceptor and electron-donor organic materials are sandwiched between two electrodes. The nanostructure of the blend is considered crucial for the cell performance since the electron-donor and electron-acceptor materials must be in an intimate contact at distances below 10 nm.

ST said it plans to use Fullerene as the electron-acceptor material and an organic copper compound as the electron-donor.